As a height adjusting device for a vehicle seat, there is known a height adjusting device for a vehicle seat, which includes two pairs of spaced apart forward and rearward linkage members bridged between side frame sections of a seat cushion frame of the vehicle seat and two pairs of spaced apart brackets of upper rail members of a track mechanism for allowing the vehicle seat to be slid forward and rearward in an interior of a vehicle, a first connecting shaft interconnecting the rearward linkage members and supported to the side frame sections of the seat cushion frame, a second connecting shaft interconnecting the forward linkage members and supported to the side frame sections, and an operating knob attached to one of the side frame sections of the seat cushion frame, and which is adapted to cause a height of the vehicle seat to be moved vertically by operating the operating knob (Japanese Patent Application Laid-Open No. 2001-138780).
The height adjusting device further includes a pinion gear arranged within the seat cushion frame, a sector gear pivotally supported through a supporting pin to the side frame section of the seat cushion frame and meshed with the pinion gear, and a linkage rod coupled at one end thereof to a portion of the sector gear which is offset from the supporting pin of the sector gear, and coupled at the other end thereof to one of the rearward linkage members.
In the height adjusting device, the first connecting shaft for interconnection of the rearward linkage members is formed of a pipe and the rearward linkage members are supported to the first connecting shaft which is bridged between the spaced apart side frame sections of the seat cushion frame.
However, in the conventional height adjusting device, it will take a lot of labor to cause the rearward linkage members to be held in position to the first connecting shaft, and cause the first connecting shaft to be supported to the side frame sections of the seat cushion frame. In addition, the first connecting shaft is not supported to the side frame sections with reliability.